Electron tube of the toroidal type



Feb. 24, 1948.

I. M. KANE ELECTRON TUBE OF THE TOROIDAL TYPE Filed May 6, 1946INVENTIOR [rWl'Jz A1. Kane. BY 1%; h- Goa-a ATTORNEY Patented Feb. 24,1948 ELECTRON TUBE OF THE TOROIDAL TYPE Irwin M. Kane, Brooklyn, N. Y.,assignor of onehalf to Charles H. Strange, White Plains, N. Y.

Application May 6, 1946, Serial No. 667,672

4 Claims. 1 This invention relates to a new and better time ofelectronic tube.

One object of my invention is to provide an electronic tube that becauseof its shape permits greater cooling surfaces than heretofore.

One object of my invention is to provide an electronic tube which willcarry relatively great power for its size.

Another object of my invention is to provide an electronic tube ofrelatively compact dimensions which can supply large amounts of highfrequency power when used in circuits designed to generate highfrequency currents.

A further object of my invention is to provide an electronic tube whichwill have an extraordinary life period under strenuous operatingconditions.

A still further object of my invention is to provide an electronic tubeof new and novel design.

Other objects and advantages of this invention will become apparent asthe specifications proceed.

In the drawing in which similar numerals indicate corresponding part-s;

Figure 1 is a plan of m tube having fragmental portions thereof removed,

Figure 2 is a cross-sectional schematic sectional view of the tube ofFigure 1,

Figure 3 is a side elevation of a modification of my tube and Figure 4is a transverse sectional view of the modification of Figure 3, thesection being taken substantially along the line 4-4 of Figure 3.

Referring to the embodiment as shown in Figures 1 and 2, an annular orring shaped electron emission element, cathode, or filament l, which isof such size as to ofier a large emission surface is almost completelysurrounded by a hollow toroidal grid 2, thereby ofiering complete anddefinite control over electron emission from the filament to an externalanode 3. This feature makes for transconductance, or the ratio of changeof the anode current to change of grid potential, of a high value, whichis desirable.

The filament is supported by supports 4 and 4 passing through holes 5 inthe lower portion of the grid 2, so as to prevent substantial electricalcontact between the supports and the grid.

The external anode 3 is annular and of inverted U-shaped cross sectionand is constructed of metal, preferably copper. This external annularshaped anode is extremely desirable because it permits a large platesurface for the reception of tremendous electron emission. Anotherdefinite advantage is the large external 2 surface area of the anodewhich makes for greater and more rapid cooling either by a water jacketor by radial fins covering the complete external surface of the anodefor cooling by a forced air draft.

The interior of the anode is sealed off from the exterior by means ofclosure 6 of glass or other suitable material, the anode and closurebeing joined by a glass to metal seal 1 so that the anode and closureform a gas-tight envelope. The preferred shape of the closure is annularand of U-shaped cross section complementary to .the anode so as topermit a smooth vertical flow of cooling air past the envelope.

The grid is supported by a plurality of supporting posts 8 anchored inthe closure 6. One of such posts 8 passes gas tight through the closureand is provided with a prong 9 for an external connector and serves thedouble function of a support and conductor.

In a similar manner the filament supports 4 and 4' pass through theclosure and are provided with connector prongs l0 and Ill.

While I have shown the filament as a con-' tlnuous ring for a dividedflow of current between its two halves from one prong to the other it isobvious that other types of filaments may be used if suitable supportsare used.

My invention when applied to high frequency generators or communicationtransmitters will, in a manner well known in the art, give relativelylarge amounts of power with due regard to the overall size of the tubethan that now obtained with the conventional types being utilized atpresent due to the shape which lends itself to larger cooling area thanheretofore experienced.

Figure 3 shows another embodiment of my invention which comprises awater cooled anode which, because of this new and novel application ofcooling, will enable the tube to carry much higher currents than tubesused now for the purpose for which my tube is designed, i. e., as anoscillator for high frequency current generation, or other electronicapplications.

The shape and construction of the embodiment shown in Figures 3 and 4,save for the anode elements, are similar to those of a conventionaltube. My tube thus shown comprises a filament la and grid 2a surroundedby an anode 3a, all enclosed in an envelope 4a. The anode 3a comprises atightly wound coil 5a of metal tubing 6a. Adjacent turns of the coil arebrazed skin-to-skin thereby forming a continuous cylinder surroundingthe grid as does the plate of a conventional thermionic tube.

The end portions of la and 8a of the tubing 6a pass gas tight throughthe envelope 4a by glass to metal seals known to the art and serve asoutlet and inlet connectors to a cooling water circulator, not shown.Strain on the seals due to Weight of the anode is relieved by stays 9a.Electrical connection to the anode may be eifected in a number of wayssuch as by means of an anode cap 10a.

When either of my tubes is constructed as a gas filled tube otheradvantages are obtained. Due to the high cooling ability of the plate oranode, the gas in the tube will not readily be absorbed by the anode,thereby insuring a longer life period for the tube.

The invention claimed is:

1. An electronic tube comprising a hollow metallic anode, an annularcathode in the hollow thereof, and an annular grid intermediate of theanode and cathode, the anode, cathode and grid substantially having acommon axis.

2. Adoughnut shaped electronic tube comprisingan insulating envelopesection and an enclosing external anode sealed thereto, the section andanode forming an envelope, a cathode adapted to be heated, a grid andrequisite connection leads passing through the insulating envelopesection, the internal elements of the tube being annular shaped andenclosed in a doughnut or torus shaped envelope said section being ofinsulating material forming a base, the upper portion of the envelopeconsisting of an electrically conductive material sealed to the lowerportion and forming an external anode.

3. An electronic tube comprising an envelope shaped in the form of adoughnut or torus, the lower portion of which consists of insulatingmaterial and the upper portion of conducting material which functions asan external anode sealed to the lower portion, and internal elementscomprising a cathode and a grid annular shaped to conform to theenvelope, the contents of the tube permitting transconductance betweenanode REFERENCES CITED The following references are of record in thefile of .this patent:

UNITED STATES PATENTS Name Date- Acheson Apr..24, 1934 Number

